MC
Q1 A 記法：磚紅鈣，藍綠銅 Q2 C S有six outermost shell electrons = 差2粒positvie electrons from Li Q3 D 只有group 1/ 2先會react with water vigorously，仲要出到Ｙ２Ｏ即係group 1 period 數目= number of outermost shell electrons Q4 C (此為第三式) Mg + water vapour = magnesium oxide and hydrogen gas Related Knowledge : 金屬活潑程度(高至低) 鉀鈉鈣鎂鋁鋅鐵鋅鉛 氫 銅汞銀鉑金 ' '一式無尾三 (一式即metal + oxygen) ; 二式得頭三 (二式即係同水反應) ; 鎂鋁鋅鐵三 (三式為與water vapour反應); 高氫者會酸 (活潑程度高過氫的，會與酸react) Q5 B 如果係plating包住晒一個metal，咁就必定係prevent from air；　如果個plating有破損，入面既metal接觸到oxygen時，先要諗有無sacrificial protection. Q6 B Q7 Ａ 此為四式，高氫者會酸 ： Zn reacts with acid，所以唔係Ｃ同Ｄ；　acid + water = H+ Q8 A Reactivity series: Hydrogen > Copper (因為高氫者才會酸，所以C同D都錯) MgSO4唔係acid，唔會同CuO反應 Q9 C 1mol C6H12 = 18mol carbon and hydrogen atoms 9 mol O2 = 18mol oxygen atoms Q10 B 需要背；或者可以咁記：catalytic converter會為chemicals reduction and oxidation；nitrogen oxides = nitrogen and oxygen ( both harmless) carbon monoide and unburnt hydrocarbons = carbon dioxide (harmless) Q11 A overall compound's charge = 0 NF3 = N(所以呢到係+3) F3 (-3) NaNH3 = 首先諗左知既atom先，Na = +1 / H = +1，但係H3 所以+3 ，因為compund's charge =0 ，所以N = -3 Q12 B 首先，電路圖係長正短負。所以Rod I 係positive，Rod IV係negative；　而同一器皿入面會係相反，即Rod II 係negative Ions由more reactive to less reactive，即係由右去左。Mg ions去了左邊，會attach to negative rod，which is Rod II Q13 C 係Group 7 既gas入面，the reactivity decreases along the group。位於上面的gas，可以replace下面的oxide。 Q14 D redox reaction = have change in oxidation number 最簡單諗法：compound入面的ion 一定有oxidation number，不過一粒atom既oxidation number係0，所以a,b,c 都一定有redox Q15 B 係recharge，咁一定會係equation既左邊有electrons，所以會係B or D discharge : Negative electrode(Cd) will lose electrons recharge : (Cd) gains electrons Q16 A atom時more reactive = compound時more stable。四樣野都係同hydrogen反應，所以睇返4隻gases 邊個最reactive就得。 Q17 C petroleum separation : fractional distillation Petroleum is a mixture of chemicals Q18 A vinegar is weak acid (~3) ；　pH=1 hydrochloric acid from stomach lining (strong acid) sugar is not a base Q19 C Household cleaner = Ammonium hydroxide sodium is not corrosive, but explosive Q20 D oxidation number 下降= reduction 變左Ion 只係關electrons時 Pb is group 4 element，走左2粒電子都仲有2粒係入面，所以呢shell都係一樣 Q21 C molecule shape要睇bond pair and lone pair N同P／H同F既outermost shell electrons 都係一樣，所以個shape都係一樣 Q22 D you have to remember Q23 C electrolyte : dilute (1-2 M) sulphuric acid anode : Aluminium cathode : (usually aluminium is also used as the cathode in laboratory) AO CR : anode oxidation; cathode reduction Anode: 4Al + 3O2 → 2Al2O3 Q24 D 1st : standard enthalpy change of formation = varies from compounds 2nd : 如果noble gas變左compound = 咁一樣係noble gas element more stable Q25 C 2 Mg + 2HCl → MgCl + H2 0.03mol 0.02dm3 1.00M 0.02mol Mg is in excess H2 = 0.01 mol The initial rate is faster Q26 B Temperature increases = rate of reactions increase Q27 D Group 7 elements have colours Q28 C Functional group: but-1-ene (alkene) ; butan-1-ol (alcohol) Q29 C Fumaric acid + Maleic acid + the one has two COOH groups Q30 D electronegativity : 吸電子的能力 愈上愈右愈高 i.e F is the highest Q31 A It is used to make rope repeating unit of nylon-6,6 Q32 B Q33 D HCl is strong acid while CH3COOH is weak acid contact surface area愈大，rate of reaction 愈快 Mn02 is catalyst Q34 B 有gas = 可以用volume of gas 有顏色的ion = 可以用color intensity 有solid power = 先可以用turbidity Q35 A soap decreases surface tension of water Q36 A P4O10 + 12NaOH → 4Na3PO4 + 6H2O When dissolved in water, nonmetal oxides form acids: P4O10 + 6 H2O = 4 H3PO4； H3PO4 is an acid = P4O10 is an acidic oxide